Add mobile camera capture, polaroid preview, gallery save & native share

- カメラ撮影 → プレビュー(ポラロイド風白縁)→ 保存 / ネイティブ共有
- iOS / Android のネイティブ実装(共有・ギャラリー保存・FileProvider)
- iOS は共有シートのプリウォームで初回表示を軽減
- iOS Info.plist 用途説明をビルド後処理で自動付与
- Android パッケージ名ガードを有効化(ビルド前チェック)
- README を整備、.gitignore に slnx / .vscode / .utmp を追加

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Assets/Plugins/Android/jp/yourname/unity/nativeshare.meta

@@ -0,0 +1,8 @@
+fileFormatVersion: 2
+guid: 061b9862a51924ae483211b22a86e662
+folderAsset: yes
+DefaultImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Plugins/Android/jp/yourname/unity/nativeshare/NativeShareBridge.java

@@ -0,0 +1,199 @@
+package jp.yourname.unity.nativeshare;
+
+import android.app.Activity;
+import android.content.ClipData;
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.content.Intent;
+import android.net.Uri;
+import android.os.Build;
+import android.os.Environment;
+import android.provider.MediaStore;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+public class NativeShareBridge
+{
+    public static void shareImage(
+            final Activity activity,
+            final String filePath,
+            final String text,
+            final String subject
+    )
+    {
+        if (activity == null)
+        {
+            return;
+        }
+
+        activity.runOnUiThread(new Runnable()
+        {
+            @Override
+            public void run()
+            {
+                try
+                {
+                    if (filePath == null || filePath.length() == 0)
+                    {
+                        return;
+                    }
+
+                    File file = new File(filePath);
+
+                    if (!file.exists())
+                    {
+                        return;
+                    }
+
+                    Uri uri = NativeShareFileProvider.getUriForFile(activity, file);
+
+                    Intent shareIntent = new Intent(Intent.ACTION_SEND);
+                    shareIntent.setType("image/png");
+                    shareIntent.putExtra(Intent.EXTRA_STREAM, uri);
+
+                    if (text != null && text.length() > 0)
+                    {
+                        shareIntent.putExtra(Intent.EXTRA_TEXT, text);
+                    }
+
+                    if (subject != null && subject.length() > 0)
+                    {
+                        shareIntent.putExtra(Intent.EXTRA_SUBJECT, subject);
+                    }
+
+                    shareIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
+
+                    shareIntent.setClipData(
+                            ClipData.newUri(
+                                    activity.getContentResolver(),
+                                    file.getName(),
+                                    uri
+                            )
+                    );
+
+                    String chooserTitle =
+                            subject != null && subject.length() > 0
+                                    ? subject
+                                    : "Share";
+
+                    Intent chooser = Intent.createChooser(shareIntent, chooserTitle);
+
+                    activity.startActivity(chooser);
+                }
+                catch (Exception e)
+                {
+                    e.printStackTrace();
+                }
+            }
+        });
+    }
+
+    public static void saveImageToGallery(
+            final Activity activity,
+            final String filePath,
+            final String displayName
+    )
+    {
+        if (activity == null)
+        {
+            return;
+        }
+
+        activity.runOnUiThread(new Runnable()
+        {
+            @Override
+            public void run()
+            {
+                try
+                {
+                    if (filePath == null || filePath.length() == 0)
+                    {
+                        return;
+                    }
+
+                    File file = new File(filePath);
+
+                    if (!file.exists())
+                    {
+                        return;
+                    }
+
+                    String name =
+                            displayName != null && displayName.length() > 0
+                                    ? displayName
+                                    : file.getName();
+
+                    ContentResolver resolver = activity.getContentResolver();
+
+                    ContentValues values = new ContentValues();
+                    values.put(MediaStore.Images.Media.DISPLAY_NAME, name);
+                    values.put(MediaStore.Images.Media.MIME_TYPE, "image/png");
+
+                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q)
+                    {
+                        values.put(
+                                MediaStore.Images.Media.RELATIVE_PATH,
+                                Environment.DIRECTORY_PICTURES
+                        );
+                        values.put(MediaStore.Images.Media.IS_PENDING, 1);
+                    }
+
+                    Uri uri = resolver.insert(
+                            MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
+                            values
+                    );
+
+                    if (uri == null)
+                    {
+                        return;
+                    }
+
+                    OutputStream out = null;
+                    InputStream in = null;
+
+                    try
+                    {
+                        out = resolver.openOutputStream(uri);
+                        in = new FileInputStream(file);
+
+                        byte[] buffer = new byte[8192];
+                        int length;
+
+                        while ((length = in.read(buffer)) > 0)
+                        {
+                            out.write(buffer, 0, length);
+                        }
+
+                        out.flush();
+                    }
+                    finally
+                    {
+                        if (in != null)
+                        {
+                            in.close();
+                        }
+
+                        if (out != null)
+                        {
+                            out.close();
+                        }
+                    }
+
+                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q)
+                    {
+                        values.clear();
+                        values.put(MediaStore.Images.Media.IS_PENDING, 0);
+                        resolver.update(uri, values, null, null);
+                    }
+                }
+                catch (Exception e)
+                {
+                    e.printStackTrace();
+                }
+            }
+        });
+    }
+}

Assets/Plugins/Android/jp/yourname/unity/nativeshare/NativeShareBridge.java.meta

@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 91f684ffb946d402fa17a9827e6b4c5e

Assets/Plugins/Android/jp/yourname/unity/nativeshare/NativeShareFileProvider.java

@@ -0,0 +1,231 @@
+package jp.yourname.unity.nativeshare;
+
+import android.content.ContentProvider;
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.database.MatrixCursor;
+import android.net.Uri;
+import android.os.ParcelFileDescriptor;
+import android.provider.OpenableColumns;
+import android.text.TextUtils;
+import android.webkit.MimeTypeMap;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+
+public class NativeShareFileProvider extends ContentProvider
+{
+    public static Uri getUriForFile(Context context, File file) throws IOException
+    {
+        File canonicalFile = file.getCanonicalFile();
+
+        if (!isFileInAllowedDir(context, canonicalFile))
+        {
+            throw new SecurityException("許可されていない場所のファイルです: " + canonicalFile);
+        }
+
+        String authority = context.getPackageName() + ".native_share_fileprovider";
+
+        return new Uri.Builder()
+                .scheme("content")
+                .authority(authority)
+                .appendPath("share")
+                .appendQueryParameter("path", canonicalFile.getAbsolutePath())
+                .build();
+    }
+
+    private static boolean isFileInAllowedDir(Context context, File file) throws IOException
+    {
+        String filePath = file.getCanonicalPath();
+
+        File[] allowedRoots = new File[]
+        {
+                context.getCacheDir(),
+                context.getFilesDir(),
+                context.getExternalCacheDir()
+        };
+
+        for (File root : allowedRoots)
+        {
+            if (root == null)
+            {
+                continue;
+            }
+
+            String rootPath = root.getCanonicalPath();
+
+            if (filePath.equals(rootPath) || filePath.startsWith(rootPath + File.separator))
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    private File getFileForUri(Uri uri) throws IOException
+    {
+        Context context = getContext();
+
+        if (context == null)
+        {
+            throw new IOException("Context が取得できません。");
+        }
+
+        String path = uri.getQueryParameter("path");
+
+        if (TextUtils.isEmpty(path))
+        {
+            throw new FileNotFoundException("path が空です。");
+        }
+
+        File file = new File(path).getCanonicalFile();
+
+        if (!isFileInAllowedDir(context, file))
+        {
+            throw new SecurityException("許可されていないファイルパスです: " + file);
+        }
+
+        if (!file.exists())
+        {
+            throw new FileNotFoundException("ファイルが存在しません: " + file);
+        }
+
+        return file;
+    }
+
+    @Override
+    public boolean onCreate()
+    {
+        return true;
+    }
+
+    @Override
+    public String getType(Uri uri)
+    {
+        try
+        {
+            File file = getFileForUri(uri);
+            String name = file.getName();
+
+            int dotIndex = name.lastIndexOf('.');
+
+            if (dotIndex >= 0 && dotIndex < name.length() - 1)
+            {
+                String extension = name.substring(dotIndex + 1).toLowerCase();
+                String mimeType =
+                        MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
+
+                if (mimeType != null)
+                {
+                    return mimeType;
+                }
+            }
+        }
+        catch (Exception ignored)
+        {
+        }
+
+        return "application/octet-stream";
+    }
+
+    @Override
+    public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException
+    {
+        if (mode != null && !mode.equals("r") && !mode.equals("rt"))
+        {
+            throw new FileNotFoundException("読み取り専用です。");
+        }
+
+        try
+        {
+            File file = getFileForUri(uri);
+
+            return ParcelFileDescriptor.open(
+                    file,
+                    ParcelFileDescriptor.MODE_READ_ONLY
+            );
+        }
+        catch (IOException e)
+        {
+            throw new FileNotFoundException(e.getMessage());
+        }
+    }
+
+    @Override
+    public Cursor query(
+            Uri uri,
+            String[] projection,
+            String selection,
+            String[] selectionArgs,
+            String sortOrder
+    )
+    {
+        try
+        {
+            File file = getFileForUri(uri);
+
+            String[] columns = projection;
+
+            if (columns == null)
+            {
+                columns = new String[]
+                {
+                        OpenableColumns.DISPLAY_NAME,
+                        OpenableColumns.SIZE
+                };
+            }
+
+            Object[] values = new Object[columns.length];
+
+            for (int i = 0; i < columns.length; i++)
+            {
+                if (OpenableColumns.DISPLAY_NAME.equals(columns[i]))
+                {
+                    values[i] = file.getName();
+                }
+                else if (OpenableColumns.SIZE.equals(columns[i]))
+                {
+                    values[i] = file.length();
+                }
+                else
+                {
+                    values[i] = null;
+                }
+            }
+
+            MatrixCursor cursor = new MatrixCursor(columns, 1);
+            cursor.addRow(values);
+            return cursor;
+        }
+        catch (Exception e)
+        {
+            return null;
+        }
+    }
+
+    @Override
+    public Uri insert(Uri uri, ContentValues values)
+    {
+        return null;
+    }
+
+    @Override
+    public int delete(Uri uri, String selection, String[] selectionArgs)
+    {
+        return 0;
+    }
+
+    @Override
+    public int update(
+            Uri uri,
+            ContentValues values,
+            String selection,
+            String[] selectionArgs
+    )
+    {
+        return 0;
+    }
+}

Assets/Plugins/Android/jp/yourname/unity/nativeshare/NativeShareFileProvider.java.meta

@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 45b951edcbe0f4d3fb0d3c657daad36f

Assets/Plugins/Android/jp/yourname/unity/nativeshare/Please change this directory path to match your package name..txt

@@ -0,0 +1 @@
+パッケージ名に合わせてこのディレクトリのパスは変更してください

Assets/Plugins/Android/jp/yourname/unity/nativeshare/Please change this directory path to match your package name..txt.meta

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+TextScriptImporter:
+  externalObjects: {}
+  userData: 
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+  assetBundleVariant: